Blender mouse function is not working properly?
I also had this problem, and it can be fixed by simply lowering the sensitivity. Note that the reset distance is still smaller than the trigger distance, so this does not fix the problem completely, it only makes almost un-noticable and more bearable.


                     With problem                                                          Improved

The reason this happens is that the game engine, when calculating the mouse's movement, resets the mouse to the center of the screen slightly before it detects the new position.
If you do not move the mouse fast enough, the game engine resets the cursor to the center before it can detect it's movement.